Star's end / Cassandra Rose Clarke.

"The Corominas family own a small planet system which consists of one gaseous planet and four terraformed moons, nicknamed the Four Sisters. The family lives on the largest of the moons. The patriarch of the family, Phillip Coromina, earned his riches though a company he started as a young man, which began as a terraforming and mining business and then later expanded into weapons manufacture, namely the production of genetically engineered soldiers, which are sold to the various mercenary groups available for hire across the galaxy. His eldest daughter, Esme, is being groomed to take over the company when he dies, and he has three other daughters (with a different mother) as well: Adrienne, Daphne, and Isabel. When Esme comes of age and begins to take over the business, she gradually discovers the reach of her father's company, the sinister aspects of its work with alien DNA, and the shocking betrayal that eventually estranged her three half-sisters from their father. After a lifetime of following her father's orders, Esme must decide whether to agree to his dying wish--that she find and assemble her sisters for a last goodbye--and in doing so face her own role in her family's tragic undoing"-- Provided by publisher.